1. Field of the Invention
This invention relates to a process unit and an image formation apparatus provided with the process unit. The term image formation apparatus is intended to include, for example, an electrophotographic copying apparatus, a magnetic recording apparatus or an apparatus such as a micro apparatus for forming on a recording medium an image corresponding to information.
2. Description of the Prior Art
When a copying apparatus using the electrophotographic method is used for a long period of time, replacement of the photosensitive member, supply or replacement of the developer, cleaning of the charging wire and/or other adjustment or replacement becomes necessary and such maintenance works have heretofore been carried out by professional service men. Recently, however, as shown in U.S. Pat. No. 3,985,436, there has been proposed a technique for carrying out such maintenance works without relying on any professional service man to make the copying apparatus operate always in good condition. As an example of such technique, there is a method of making the various constituent members such as the charger, developing device, photosensitive drum, etc. contained in the apparatus into a unit and replacing such unit with a new one. If the apparatus is designed to permit replacement of such unit, it will also become possible to use the same apparatus body multifunctionally by preparing a plurality of such units in accordance with usages and inserting into the apparatus body a unit matching a desired usage.
However, by the user who has a copying apparatus so handling the unit, the maintenance becomes easy and the usages become wider while, on the other hand, problems may arise in the handling of the unit.
It is desirable that the unit can be maintained in a horizontal condition (a condition in which the unit has been loaded into the copying apparatus body) when it is carried or preserved after it is removed from the copying apparatus body. Because the toner storing portion is within the unit, if the unit is carried in its inclined condition or the unit is left vertically standing on a desk or on the floor, the developer may sometimes incline toward one direction. This may result in the undesirable possibility that development becomes partly impossible due to such inclination of the developer. In this case, even if the apparatus has a developer stirring member, much time will be required until the developer is made uniform and thus, the use of the copying apparatus will be limited.